Carbolite Blade Strip Hardeing and Tempering Furnaces

Hardening and tempering blade strip line

• Seven continuous heat-treatment furnaces at one of the world's leading manufacturers of surgical blades
• Each unit has four lanes, enabling several strands of strip to be treated at the same time
• The steel strip is first heated in hydrogen in the hardening section, which has two independently controlled heating zones
• It is then quenched between water-cooled plates, before being reheated to achieve tempering
• The strands run horizontally in each furnace in 5Omm diameter work tubes, with heating elements mounted horizontally above and below each tube
• Overall, the furnaces are 1160mm high x l000mm wide x 3800mm long
• Provision for heat treatment in cracked ammonia as well as hydrogen

Razor blade strip line

• Furnaces for heat treating stainless steel strip 0.1mm thick in a continuous operation for one of Japan’s specialist manufacturers of disposable razors
• The furnaces process two strands simultaneously through a pair of tubes side by side at up to 15 metres a minute while ensuring the combination of hardness, temper, ductility and flatness required by the customer
• The strip is typically 18mm to 26mm wide and 0.1mm to 0.15mm thick
• Hardening takes place at temperatures up to 1150°C in a hydrogen or cracked ammonia atmosphere
• The hardening section of the furnace, which has a heated length of 7.1 metres, is divided into six zones to provide good temperature uniformity
• The hardening furnace has a 60kW power rating, which enables it to heat up rapidly from cold
• Separate gas control equipment has been supplied for each lane
• After hardening, the strips pass through water-cooled quench blocks and are then frozen to -70°C before being tempered
• The tempering unit is 1.7 metres long and is designed so that the temperature of the two lines can be controlled independently

Continuous horizontal strand hardening & tempering furnaces

• Treating 6 strands of 1% carbon steel knife blade strip 27mm (w) x 0.635mm thick at 6.1metres/minute under cracked ammonia
• Power rating: 52kW
• Hardening:
• Maximum operating temperature: 1150°C
• Temperature uniformity: + 10°C at 1000°C
• 6 zones
• 6 process tubes positioned across the furnace width
• Tempering:
• Maximum operating temperature: 500°C
• 9 zones - 3 heated sections with 3 zones
• 6 stainless steel tubes